Hello my name is ***** ***** I will help you with this.
What is it you want to achieve please Mr Troth?
What is your number and I can call?
You have no contract with the agent. Therefore you are not bound by any written agreement between the agent and builder.
Therefore you can write to the agent and say that they are in breach of contract by failing to act with all reasonable skill and care. I would give 28 days notice.
Unless you have signed a contract then its not binding and you can end it, but to be fair give 28 days notice.
If you have a written contract then you should see what it says about termination. But in any event if there is a written agreement then you can still write and say he is in breach and that it is significant and you want to end it.
I hope this helps.
You dont need to let me know, if you can just email customer services?***@******.***